What’s Berkshire Hathaway’s expected life?

Berkshire Hathaway has a lot of equity: its book value is about $125 billion. And since equity is forever, it makes sense for Berkshire to have a very long time horizon when it comes to buying assets. But still:

Berkshire Hathaway Inc.’s Warren Buffett, who agreed to buy Burlington Northern Santa Fe Corp. in his biggest takeover, said the railroad’s results in the next 100 years will justify a $26 billion bid that’s “not a bargain.”

“It’s a good asset for Berkshire to own over the next century,” Buffett said in an interview with Charlie Rose.

It’s refreshing to see the 79-year-old Buffett taking such a long view. But the fact is that Berkshire Hathaway is not going to exist in anything like its present form in 100 years’ time. It’ll probably last no more than 10 years after Buffett dies before it’s broken up into various component parts. And when he gives quotes like this to Charlie Rose, it seems as though he’s somewhat in denial about what his legacy is really going to be.

The minute that Buffett dies, Berkshire becomes a large conglomerate, and will trade, like all conglomerates, at a discount to its sum-of-the-parts valuation. Sooner or later, Berkshire’s CEO will be persuaded to monetize the difference, and the storied company will come to its natural end. That’s no bad thing: it’s intrinsic to the nature of capitalism, which Buffett loves. But it does mean that buying companies on a 100-year time horizon is somewhat unrealistic.